.\"	$NetBSD: _lwp_wait.2,v 1.4 2008/04/30 13:10:51 martin Exp $
.\"
.\" Copyright (c) 2003 The NetBSD Foundation, Inc.
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.\" This code is derived from software contributed to The NetBSD Foundation
.\" by Jason R. Thorpe of Wasabi Systems, Inc.
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.Dd January 13, 2003
.Dt _LWP_WAIT 2
.Os
.Sh NAME
.Nm _lwp_wait
.Nd wait for light-weight process termination
.Sh LIBRARY
.Lb libc
.Sh SYNOPSIS
.In lwp.h
.Ft int
.Fn _lwp_wait "lwpid_t wlwp" "lwpid_t *rlwp"
.Sh DESCRIPTION
.Fn _lwp_wait
suspends execution of the calling LWP until the LWP specified by
.Fa wlwp
terminates.
The specified LWP must not be detached.
If
.Fa wlwp
is 0, then
.Fn _lwp_wait
waits for any undetached LWP in the current process.
.Pp
If
.Fa rlwp
is not
.Dv NULL ,
then it points to the location where the LWP ID of
the exited LWP is stored.
.Sh RETURN VALUES
Upon successful completion,
.Fn _lwp_wait
returns a value of 0.
Otherwise, an error code is returned to indicate the error.
.Sh ERRORS
.Fn _lwp_wait
will fail if:
.Bl -tag -width [EDEADLK]
.It Bq Er ESRCH
No undetached LWP can be found in the current process corresponding to that
specified by
.Fa wlwp .
.It Bq Er EDEADLK
The calling LWP is the only LWP in the process.
.It Bq Er EDEADLK
The LWP ID specified by
.Fa wlwp
is the LWP ID of the calling LWP.
.It Bq Er EINTR
.Fn _lwp_wait
was interrupted by a caught signal, or the signal did not
have the
.Dv SA_RESTART
flag set.
.El
.Sh SEE ALSO
.Xr _lwp_create 2 ,
.Xr _lwp_exit 2
.Sh HISTORY
The
.Fn _lwp_wait
system call first appeared in
.Nx 2.0 .
